Re: [PATCH 1/2] usb: dwc3: Tell xhci-plat when the core lost its state on resume

[sashiko-bot@kernel.org]

> From: Arun Iyengar <aiyengar1990@gmail.com>
> 
> In host mode without wakeup, dwc3_suspend_common() tears the core down
> with dwc3_core_exit() and dwc3_resume_common() initialises it again, so
> the xHCI registers are back at their reset values when xhci-plat resumes.
> xhci_resume() is not told about this: it writes the saved operational
> registers back and asks the controller to restore its internal state
> (USBCMD.CRS), which cannot work on a freshly reset core. It fails with
> USBSTS.SRE, and xhci_resume() only then falls back to a full reset:
> 
>   xhci-hcd xhci-hcd.1.auto: xHC error in resume, USBSTS 0x401, Reinit
> 
> xhci-plat already has a way for the glue to report this:
> xhci_plat_priv.power_lost, which cdns3 sets the same way. Set it from
> dwc3_resume_common() whenever the core was re-initialised (and clear it
> when it was kept running for wakeup), so xhci_resume() goes straight to
> the reset and re-init path.
> 
> Signed-off-by: Arun Iyengar <aiyengar1990@gmail.com>

Sashiko has reviewed this patch and found no issues.

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